Pullups are termed a functional exercise because they mimic the pulling motions you sometimes use during everyday life. Because pullups work all your back muscles at once, plus your shoulders and the pulling muscles in your arms, they also help you get through your workout quickly and efficiently. However, if you're not quite up to hefting your entire body weight or don't have a pullup bar to work with, you can get similar benefits from alternative exercises.

Lat Pulldowns

Lat pulldown machines come with regular, narrow, underhand and wide grips. Switching grip positions subtly influences which muscles bear most of the load, but all the grip positions serve the same basic function as pullups: giving you a way to pull down against resistance. Lat pulldowns mimic the motion of doing pullups so exactly that they work all the same muscles.

Weighted Rows

A weighted row machine positions your chest against a vertical pad, while you grip two handles positioned in front of your shoulders. When you pull back on the handles, lifting the weight plates they're tethered to, your latissimus dorsi -- the same muscle that does most of the work during pullups -- activates powerfully. Rows also work the same shoulder and arm muscles that pullups target, albeit at a different angle.

Dumbbell Rows

If you don't have access to a weighted row machine, you can do the same exercise with a single dumbbell and a weight bench. Place one knee on the bench and lean forward from the hips, resting one hand on the bench to support your torso. Hold the dumbbell in your free hand. Keeping the elbow of that arm close to your body, pull the weight straight up, halfway between your shoulders and hips. Stop when your elbow is even with your spine, then lower the weight back to the starting position.

Rowing Machines

Rowing machines, or rowing ergometers, are more than just a cardio workout. Done properly, working out on a rowing machine works the same muscles that would activate during a weighted row or while doing pullups. However, because you're performing the same rowing motion many times against light resistance -- as opposed to just a few times against heavy resistance -- rowing machines develop more muscular endurance than strength.

Elastic Resistance Bands

You can use elastic resistance bands to mimic the pullup motion, too, as long as you have a door anchor that's specially made to work with your resistance bands. Thread the band through the door anchor's loop, then lay the anchor across the top of a door and shut the door, trapping the stopper end of the anchor on the other side of the door. Kneel on the floor facing the door, holding one end of the elastic resistance band in each hand. Lean forward slightly from your hips and pull both ends of the band down just in front of your shoulders, then extend your arms back overhead to complete one repetition.